The present invention relates to a novel method for detecting optical image information and, more particularly, to a method for processing optical image information by a photoelectric device, wherein a specific image processing is performed by a photosensitive material itself that serves as a photoreceptor. Still more particularly, the present invention is concerned with an image detection method in which a photosensitive chromo-protein having visual functions such as bacteriorhodopsin is used as the photosensitive material and in which optical information processing function peculiar to such a protein is effectively utilized.
Current progress in fine processing techniques and photolithography has brought about a remarkable increase in the recording density of image information. At the present stage, however, development of high-density photo-sensors and high-density recording elements mostly relies upon fine processing technology which employs silicon as a photosensitive material, so that the function of the photosensitive material is ruled by the characteristics of silicon and its junction devices. Consequently, processing of input image information is enabled by electronic circuit manipulations and computer software, although the recording density can be improved by advance in silicon technology.
Charge coupled device based on silicon is a typical example of image-sensing device which can detect image information at high density. In this type of device, optical signal is converted into a quantity of charge and is electrically stored as a memory. The stored information is read by a circuit through a linear serial scanning of memories and is then displayed as two-dimensional information. This method employs a method in which memory is reset at a predetermined time interval in order to trace a change in the information in relation to time.
The conventionally used photosensitive material which is mainly made from silicon, however, does not possess any processing function necessary for identification of information, such as detection of mobile image and extraction of edge lines which are inherently possessed by visual cells of living creatures, which would be demanded of an image information processing system in near future. This limits potential development and realization of the future photosensitive device as so-called intelligent sensor. As a result, electric circuits for processing output information and computer networks are heavily burdened in order to enable a solid-state device photodiode to work in a visual information processing system. For instance, a pattern recognition and matching operation essentially requires, as the first step, pick-up of the outline of the object. Extraction of the outline component is a highly important factor of pattern recognition. In addition, detection of motion of the object requires a real-time extraction of only the dynamic or mobile components of the optical information. The image extraction must essentially and significantly be backed up by auxiliary functions such as adaptation and profile contrast stressing. These functions are important factors which are inherently possessed by vision of living creatures and are goals to be attained by photo-sensors of the next era. Such functions, however, can hardly be achieved by solid-state devices which are presently available such as photo-diodes.
T solve the above problem, the invention of the present application seeked the above function for biological material without sticking to use of a solid device or an electrical circuit, and processed with this study under consideration of obtaining some elements having an information processing means according to the visual sense.